In the manufacture of raw tape thermoplastic film bags, a channel or tunnel structure containing the draw tapes is provided around the mouth of the bag by hemming or turning in the edge portions of the two panels forming the front and back of the bag. A method and apparatus for providing these hems is disclosed in the aforesaid U.S. Pat. No. 4,617,008 and the disclosure is incorporated herein. In that patent a stationary plate and stationary triangles mounted on the plate are used to fold or otherwise direct the web of thermoplastic film during the folding operations. While the method and apparatus disclosed therein produce satisfactory draw tape bags, it has been found that for higher bag manufacturing speeds and for larger draw tape bags such as draw tape trash bags (i.e. more than 120 bags per minute and 24" wide bags) that the drag on the thermoplastic film passing over the stationary edges of the hem forming apparatus was so great that the tension resulting in the film in some instances caused a weakening of the bag material around the punched holes through which the draw tapes are pulled when the bag is closed.